Process of purifying tin scraps preparatory to detinning the same.



a citizen of the; Empire of Germany, res'ic, mg in Crefeld,'in the Kingdom of Prussia tainnew and useful Improvements in ,Proc} essee of Purifying Tin Scraps Prep,aratory totDetinningthe Same, of which the follow-f- ;i ng is'aspecificationn.

' varnish, polish, paint, dirt, paper, straw,

- was hitherto carried out in separate wash qy' to vbe deprived of tin, being packed,iiiiithe :loosest and bulkiest state possible, into, haskets or,rotating drums, and in the ffilled. ,f baskets or drums being dipped into resera voirs-r-filled" with thewashing liquid 'in vmwhichboth the-washingliquid and themanace."

moss s or seamin 1am, sonar To whom, it mag concern: Be it knowntha-t I, CARL VON Dali L11}; E 3' and Empire of Germany, have invented ,cer-

The extr ction. oftin from waste scraps presupposes, as is well known, the purification of the scraps to be treated,- from fatty and oily'substances, as well as from small piecesof wood, etc. This purification ing apparatus and consisted in the material terial to be-treated were exposed to an,enerj gic motion, Such washing liquids were in" the form of alkaline lyes for removing fatty and oily substances, and warm and cold water for the subsequent rinsing. In that way, a kind of elutriating-action was obtained,-that is to say, not only were impurities soluble in the washing liquid, such as fat and oil, removed from the material to be treated, but'also impurities insoluble in the washing liquid and adhering to the said material, such as paint, paper, varnish, polish, straw, sand and dirt, were separated and removed from the material to be treated by a kind of mechanical process. On account of the great bulk of'the material, this treatment necessitated, as will be readily understood, the use of large tanks and mechanical appliances, and therefore large installations and working expenditure.

The object of the process according to this invention is to subject the material to be treated, to washing, not as hitherto in a The said new process consists in the packets being piled up in a closed vessel and in forcing the washmg liquid through the sinuses sommmmesns same.

"t r cpeat'edly pressure ordrawing -itthrough them by the action of a vacuum -or"sjuc-t1on; The great advantage of this new processjwh'ichf does'away with the installa ti o'ns hitherto required, necessitating, a great dealt of space and expense, is. obvious. iHithe'rtofthe ,carrying out of this process has beenprevente'd by the fact that a complete purification of the material treated ;c" a nn,( tf'be, "etfected, asFth'e. compressed mate; T1211, exerc ses a; kind of filter-action and back the undissolved impurities. have found, however, that although such a complete purificationas that formerly obitained with'the material in the loose form, ear-11 a be obtained by my new process and althoughfin' fact the impurities such as paper, wood, ,sand, etc,, which are insoluble "in; the lyeand in: the water actually remain iinl the. solidpackets, these impurities, insoluible:: l. "tlil jwashing liquid, do not forinan iobstacleiby theiri mere presence in the pack- 'ets, to; the subsequent complete tin-extrac- 'tionprocess 'loylchl orin as long asthe impurities arejcompletelydeprived of fat and ,oil land removed from the surface: of the'ma 7terialto betreated, This discovery is a surprising, one,; for. hitherto ,wasge'nerally consideredjthatthe material to be deprived of tin, must be completely purified from all foreign matter such as dirt, fat, ete.-,--i:f=it-- was desired to bring about a complete extraction of tin'and so obtain an unobjectionable product. As a consequence of this discovery, it is possible to dispense with the washing of the material in a bulky loose state, and with the large and costly apparatus formerly necessary, and to effect the purification of the material in compressed packet-form. Thus, on the one hand, space and money are economized, and on'the other hand, it is possible to have the purificationprocess carried out in the same vessel 1n which the drying and chlorination are subsequently eii'ected.

The process of forcing liquids by pressure or drawing them by suction or vacuum through packets formed of the material to be deprived of tin is well known in itself, both for the chlorination and for the subsequent washing to get rid of the last traces of the tetra-chlorid of tin, and such subsequent washing and drying has been carried out in the vessels in which the chlorination has taken place. But ,,although it might have been thought obvious to apply mam curios.

p a v of L ter Ea nt- Pateiit'ed June' 27 1911, Application meanemtert, i916. sefialfin'o. 595,544.

.that process to the first washing or purification of the material from which the tin was purpose. The fact that the said cheap and simple process for -washing the material. from which tin is to be extracted has not been hitherto appliedin practice, and that instead of it was used a considerably more expensive process with a large and costly installation, indicates that it was considered that the apparently only complete Washing that could be obtained with that process, could never be suflicient for a subsequent complete extraction of tin by means of chlorin. Asa matter of fact, the surface of the material to be treated, does not get,- in the new process anything like the bright appearance which is obtained when washing the materials to be treated in a bulky loose state in separate rotating or m'ovable apparatus. On the contrary, owing to the filtering action of the packets, the impurities such as paper, wood, sand, varnish, etc., which are insoluble in the lye although they are rendered soft and are separated from the surface, remain in the packets, and it is therefore natural to assume from the experience generally obtained hitherto with insufiiciently purified material that such an apparently insuflicient washing process in packet-form was unsuitable for subsequent extraction of tin. Experiments have proved that all impurities do not constitute an obstacle'to the complete extraction of'tin, but

that the chief points are, with the assistance of the washing liquid, firstly, to dissolye completely and to remove the oily and, fatty impurities, and secondly, to render the surstraw, small pieces of wood, etc. Thefact that the latter remain in the packets in the separated state, is as already stated, of no importance for the subsequent chlorinationprocess, provided the impurities have been deprived of all oil and. fat, which is completely effected by the present process.

I claim: I

1. The process herein described of wash ing tin scrap and similar material from which tin is to beextracted, which consists in compressing the'material into bundles or packets and then forcing the washing liquid before chlorination through the compressed material.

2. The process herein described of washing tin-scrap or similar material from which tin is to be extracted,whichconsists in compressing the material into bundles or packets, then forcing the washing liquid .before chlorination through the compressed material, and subsequently. carrying out the drying and chlorination of the purified material in the same vessel in which the washing was eflected. I

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

CARL VON DE'R 'LINDE.

Witnesses ELISE KODBUROH, HENRY QUADFLIEG. 

